Development of Blood Pressure Imager We propose a new technology to measure blood pressure (BP) called the Blood Pressure Imager (BPI) that does not require cuffs or expensive equipment, and that can be used by untrained individuals. The primary innovation rests on the application of cutting-edge optical tactile sensor technology to the basic observation that blood pressure (BP) has a direct relationship to the outward force on the arterial wall, which, in turn, affects the deformation and forces imposed on the tactile sensor array by the skin surface above, particularly at locations such as the region above the radial artery. By integrating high-resolution GelSight optical tactile sensor patch together with signal processing software, BPI can provide precise measurement of skin surface motions and forces exerted by the underlying pressure wave and provide an accurate measure of systolic and diastolic blood pressure. The development and validation of the BPI will be a collaborative project between researchers at the Massachusetts Institute of Technology and Tufts University School of Medicine. The specific aims of the proposed product development include (1) To optimize existing portable BPI to measure blood pressure accurately in arterial phantoms; (2) To test and further optimize the portable BPI in animal models; (3) To miniaturize the BPI into a wearable device that will connect with mobile phones; (4) To validate the wearable BPI against intra-arterial blood pressure in a dynamic clinical setting; and (5) To validate the wearable BPI i clinic and home/low resource environments. The advantages of BPI over the existing devices are: (1) The BPI will be a cuff-less device that can used by untrained individuals; (2) It will provide instantaneous BP continuously over time and a direct measure of systolic and diastolic blood pressure; (3) It will measure BP over multiple heart beats and respiratory cycles to provide accurate measure of BP and valuable information on beat-to-beat BP variability; (4) It will be a novel wearable device that can be integrated with mobile phones and the data can be transferred instantly over low- bandwidth cellular connection for online/remote management of hypertension; (5) With no moving parts and built from off-the-shelf components, connected to existing mobile phones, and battery-driven, the BPI will be affordable and not require additional power source; (6) With relatively minor design modifications, the BPI could provide 24-hour ambulatory monitoring of BP and has potential for use in acute, dynamic inpatient settings as an alternative to invasive monitoring.